Poorer Health of Surgery Patients on Medicaid May Alter Law’s Bottom Line

WASHINGTON — Surgery patients covered by Medicaid arrive at the hospital in worse health, experience more complications, stay longer and cost more than patients with private insurance, a new study has found.

The study, by researchers at the University of Michigan, may offer a preview of what to expect as millions of uninsured people qualify for Medicaid under the Affordable Care Act.

Although Medicaid patients in the study were generally younger than the privately insured patients, they were twice as likely to smoke and had higher rates of conditions that made surgery riskier. Those conditions, which can arise from years of poor health habits, include diabetes, lung disease and blood vessel blockage.

The study, published this month in the journal JAMA Surgery, analyzed data on nearly 14,000 patients who had operations at 52 hospitals in Michigan from July 2012 to June 2013.

Dr. Darrell A. Campbell Jr., the chief medical officer of the University of Michigan Health System, who led the study, said: “The Medicaid patients were sicker, and they did not do as well following surgery. They stayed in the hospital longer, and that increases the cost.”

Michigan has just expanded Medicaid, and nearly half a million people may become eligible for coverage. Since the state began taking applications on April 1, more than 237,000 people have enrolled.

“We supported the expansion of Medicaid because it means that we can get patients into medical care and get them into optimum shape for an operation,” Dr. Campbell said in an interview. “Being a heavy smoker predisposes you to get pneumonia after an operation. For a diabetic, if blood sugar is out of control, that increases the chances of a wound infection after surgery. If we can address these issues preoperatively, we can cut down the problems we see after an operation.”

About half the states have expanded Medicaid, and the White House is urging others to do so, noting that the federal government will pay the full cost until 2016 and at least 90 percent in later years.

The Michigan researchers reported these findings:

■ In the month after their operations, the Medicaid patients had two-thirds more complications and were more than twice as likely to die, compared with those on private insurance.

■ Medicaid patients typically needed extra time in the hospital — three days, on average, rather than two — and were more likely to return after going home from surgery.

■ Medicaid patients “had more emergency operations and used 50 percent more hospital resources than patients with other kinds of insurance.”

The findings have financial implications for hospitals, which are often paid less than the full cost of caring for Medicaid patients.

Kara Gavin, a spokeswoman for the University of Michigan Health System, said that many people who previously received charity care were now enrolled in Medicaid.

Previous studies suggest that many people will use the new coverage to obtain medical care for conditions that went untreated while they were uninsured.

The new health law reduces special payments to hospitals serving large numbers of low-income patients, on the assumption that many of the uninsured will gain coverage through Medicaid.

But hospital executives are unsure that the savings will materialize. Dr. Campbell said the cuts could create serious financial problems for hospitals treating large numbers of Medicaid patients.

Recent research in other states has raised similar questions.

In Oregon, researchers examined what happened after the state expanded Medicaid to people selected through a lottery. Contrary to expectations, those who gained coverage made more visits to hospital emergency rooms, even for conditions that could have been treated by primary care doctors in the community.

Obama administration officials said they were planning a public education campaign to teach people how to use their new coverage, and one major objective is to discourage the use of emergency rooms as a source of routine care.

A version of this article appears in print on , on Page A20 of the New York edition with the headline: Poorer Health of Patients on Medicaid May Raise Costs. Order Reprints | Today’s Paper | Subscribe